Religious sects are not immune to this. In fact, these can often be worse than most, as dozens, hundreds, or even thousands of actual deaths are not an uncommon occurrence as a result of these arguments.
Note that a Real Life subject like this can be somewhat touchy, so please, use caution when adding examples.
The Bible has more of this than the rest of this page combined.
A really interesting case appears concerning versions of The Bible. For instance, there are those who consider the King James Version the only Holy version and believe you will go straight to Hell if you read the New Living translation, The American Standard, or any other translation. On the flip side you have those "enlightened" Christians who refuse to use a version of the Bible published prior to 1988.
Just those? How about the people who believe it should be written/read in nothing but the original languages (for those not paying attention, that's predominantly Hebrew and Greek, with other languages thrown in all over the place) vs. the people who believe it should be written/read in one's own language.
Think of it like a movie. The Torah is the first one, and the New Testament the sequel. Then the Qur'an comes out, and it retcons certain key bits of the last one like it never happened. Thereís still Jesus, but heís not the main character anymore, and he didn't die but was taken up alive to Heaven (or maybe he didn't, it's not clear), and the messiah hasnít shown up yet, although Jesus will probably (it's not clear) show up again with him (or maybe the messiah is Jesus and the other guy will show up with him—look, the filmmaker focused a lot on the artistry this time and put everything in rhyming verse, which while cool muddled things up a bit). Jews like the first movie but ignored the sequels. Christians think you need to watch the first two, but the third movie doesnít count—the style was weird, even more so the production team, and the big retcons screwed not only with the canon they liked but also with the extensive fanon they had built up. The Muslims think the third one was the best but appreciate the first two as well (or are supposed to, a few have gotten a little bit rabid in their fanboyism), and Mormons liked the second one so much, they started writing fanfiction that doesnít fit with ANY of the series canon.
Filioque. (See the other wiki here. The phrase literally means "and from the Son". The dispute is whether the Holy Spirit (the third Person of the Trinity) proceeds from the Father (the first Person of the Trinity) or from the Father and the Son (the first and second Persons of the Trinity). That's it. Yet that (together with some more political disputes) resulted in the division of Orthodox Christianity from Western Christianity.
There was considerable resentment that the pope introduced the -que (which had often been used in the West) without consultation.
After that, you get into the fun times of the Reformation. Martin Luther vs. Catholicism, John Calvin vs. Martin Luther, a whole bunch of guys vs. Calvin, the sectarianism goes on and on.
... Catholic vs. Anglican, i.e. can you get a divorce or not if your name is Henry VIII...
And now, the more "liberal" Protestant churches are splitting over the issues of homosexuality and the ordination of women.
Call it a GRINDED base. There was a time that churches split over the question if the snake REALLY spoke in Genesis, if there could be flowers on the altar, and over how often you should celebrate communion. Many churches are disappearing because their followers keep dying away, with the remaining few going to bigger churches.
There's even large-scale division as to which books should be included in the canon of Scripture itself: Are the Apocrypha considered canonical (Catholic / Orthodox), non-inspired but still edifying (Reformers / Anglicans), or downright heretical (most other Protestants)? Was Martin Luther wantonly throwing away the books of the Bible he didn't like, or restoring it to the original version of the Jewish Rabbis and Church Fathers?
Don't even bring up the question of which parts of the Bible should be taken literally.
Among a lot of mainstream and minority churches, believers are split along the lines of: "We should be prepared to compromise in order to win over new believers."/"This isn't a popularity contest, we don't budge an inch."
Buddhism - Theravada or Mahayana? Or maybe Tibetan? or Zen?
Rinzai, Obaku or Soto Zen?
Which Sutra? The Diamond? The Flower Sermon? One of the lesser ones?
Is Reincarnation real or does it not matter?
A common question is whether it's Reincarnation or Rebirth and which one do Buddhists believe.
Is the Buddha a God?
It's actually official doctrine in the Hindu religion that Buddha was an avatar of the god Vishnu. Whether all Buddhists believe this, though, is another story
Hindu doctrine states that Vishnu incarnated as Buddha to teach a false doctrine to ensnare demons.
That's an oversimplification. Many, probably most, Hindus came to accept Buddhist doctrine (or aspects of it) as valid, and the Brahmin priests were forced to accept that. The realBase Breaker among Hindus when it comes to Buddhism is whether Buddhism actually counts as a separate religion, or whether Buddhists are just "Hindus in denial, going by a different name," as some Hindus have argued (needless to say, most Buddhists would be rather annoyed at this characterization).
Is Buddhism a religion or a philosophy? Is Buddhism theistic, atheistic, or neutral?
Most Asian Buddhists seem to lean more towards religion, more often than not. It's often white Western Buddhists who prefer to call it a "philosophy."
Can you be Buddhist and another religion?
Sunni vs. Shiite Islam.
Ahmadiyah vs. the mainstream Islam. (Depending on the population, 'mainstream' can be Sunni or Shi'i.)
Sufism ("esoteric") vs. mainstream ("literal") Islam.
Universal caliphate vs. nationalist governments.
If nationalist, theocratic government or secular government.
Instate Sharia as the sole law, or allow secular philosophies in law.
And among those advocating Sharia: Sunni or Shia? If Sunni, Hanafi, Hanbali, Maliki, or Shafi`i or something else?
Even more may happen once the new revision and translation of the Roman Missal (the official framework of the Mass that all churches in America work from), meant to bring the wording of the Mass more in line with the original Latin and that changes some of the rituals, is introduced in November 2011.
Heck, even mentioning pretty much any rumored apparition of the BVM after Fatima can start a flame war.
Just AFTER Fatima? Try bringing up "the Third Secret", or whether "the Consecration" was "validly" perormed.
Some of these views can and do exist within extended (and even immediate) practicing Catholic families. Talk about awkward holiday dinners...
Vatican II? Try the First Vatican Council; a dazzling array of Catholic groups split away from the rest of the Catholic Church over the issue of Papal Infallibility in the 19th century, and since then they've splintered and suffered schisms among themselves. It's not uncommon to find that some of these churches consist of only a handful of people; usually, the longer and more ostentatious the title, the tinier the sect (the Supreme Patriarchate of the True Apostolic Catholic Episcopalian Church of Western Europe, North America, Great Britain and All Her Overseas Dominions will invariably consist of a few dozen people at most). In terms of doctrine they can range anywhere from ultra-liberalism to ultra-conservatism, from fairly standard, if tiny Christian denominations to curioushybrids of New Age and occultist beliefs with Catholicism. The more extreme groups tend to be obsessed with Apostolic succession and can (through a long complex system) trace their origins back to the mainstream Catholic Church and in theory right back to the apostles and will frequently excommunicate one another in disputes about this. Woe betide the foolhardy journalist who refers to one of them as a "self-proclaimed" Bishop - in fact, according to Catholic Canon Law these clerics are deemed to be just as validly ordained in the eyes of the Vatican as your local Catholic parish priest.
If you're a Hindu, try mentioning the Kama Sutra to your pandit (that's a priest, for any non-Hindus reading this) or any fellow Hindus who happen to be elderly. They will almost definitely react in a horrified, scandalized fashion. This is due to the fact that even though Hinduism used to have much more "modern" (for lack of a better word) view of sex in ancient times, over the past few centuries, both conservative Muslim and Victorian British conquerors imposed a much more conservative view of sexuality after they conquered India, and this conservative view still pervades much of Hindu society today.
The more conservative Hindu factions in India (although that's a Broken Base in and of itself) vs. the much more liberal form of Hinduism practiced in Guyana, Trinidad and the other Caribbean nations with large Indian-descended populations (the British brought a lot of Indians to the Caribbean as servants). The Indian Hindus will accuse Caribbean Hindus (particularly Guyanese and Trinidadians) of "acting white", being "not Indian enough," and of being too liberal and permissive. Meanwhile, the Caribbean Hindus will accuse the Indian Hindus of being "old-fashioned," "ultra-conservative," and "too strict."
To clarify for non-Hindus, virtually no Caribbean Hindu practices vegetarianism unless it's a religious holiday, with the only exceptions being the priests. Caribbean Hindus typically abstain from beef or pork, but have a long culinary tradition with other meats. Caribbean Hindus also tend to have much more liberal views of sexuality than modern Indian Hindus (for the reasons why India became conservative on those issues, see the Kama Sutra entry above on this page). Finally, and this is the big one that seems to be a majorBerserk Button for many Indian Hindus, Caribbean Hindus generally do not speak Hindi at all, and grow up speaking Caribbean English dialects as their native language. Hindi remains a liturgical language among Caribbean Hindus (much the same way Hebrew is for American Jews, or the way Latin used to be for the Catholic Church), but most Caribbean Hindus know only a handful of Hindi words at most. This tends to really result in Flame Wars where Indians and Indo-Caribbeans end up at each others throats.
The non-religious in general. It been said that getting a group of atheists to agree on something or to unite for or against something is like herding cats.
Specific examples: should we call ourselves atheists or agnostics?note Nearly all non-believers agree there's at least some chance of god existing, but self-proclaimed atheists feel the term 'agnostic' implies a greater likelihood than they're comfortable with, much like calling themselves 'unicorn agnostics' would. Should we work with religious believers, against them, or both? Are all ideas fair game in the marketplace of ideas, or should we be sensitive to the strong attachments people might have to their beliefs?
Even Richard Dawkins gets this. He seems to be portrayed in the media as one of the figureheads for Atheism and certainly has a large following, however a lot of atheists find him unpleasant and think he gives a bad image of atheism.
Raise the question of whether or not God even exists, and if so, how involved He/She/It is in the lives of humans. (Especially in "religion vs. science" debates). Watch the fur fly, along with vicious insults... and chairs.
The Uniting Church in Australia (UCA), the third biggest church in Australia, is somewhat broken over whether or not gay and lesbians (in same-sex relationships) can be ordained as ministers. It's been debated since 1982.
The East-West Schism, sparked by a number of Broken Base matters of their own, is the greatest example to be found in the history of Christianity. The differences in faith created mutual distrust between the Catholic and Orthodox churches and sparked many wars during the course of several centuries.
Albeit that what set it off was a dispute over who was the boss in the church (The Bishop of Rome, i.e. the Pope vs. any archbishop of his own church) rather than a dispute about what was in the Bible per se.
In the 17th century, Nikon, the Patriarch of the Russian Orthodox church, worked on several reforms to update the Russian liturgy to match the Greek. These reforms were protested by a group that eventually became known as the Old Believers. Although initially outlawed and persecuted, the Old Believers' religion survived and they still continue their traditional ceremonies distinct from mainstream Orthodoxy.
The reason why Martin Luther brought about Lutheranism and the Protestant Reformation is hotly debated by theologians and historians due to how the corrupt the Catholic Church was at the time and his rivalry with a fellow priest over gaining a position which was a fast track to becoming a Cardinal.
Of course, Luther's ideas would have remained a mere "dispute of monks" (as some Catholic put it) had it not been for the recent invention of the printing press; without the press, the only people to hear about it would be a few monks and theologians, who would proceed to write angry letters to each other until the new ideas were either accepted or forgotten. With the printing press, the public at large got wind of it within days, and that changed society forever. Neat, eh?